Gasification is a process that converts organic- or fossil-based carbonaceous materials into fuel gases (e.g., carbon monoxide, hydrogen, methane, etc.). Depending on the feedstock, additional gases may be generated, such as carbon dioxide and nitrogen. Gasification is achieved by reacting feed material (e.g., wood, coal, municipal solid waste, recycled tires, refuse derived fuel (“RDF”), or the like) at high temperatures (e.g., >700° C.), without substantially any combustion, and with a controlled amount of oxygen and/or steam. The resulting gas mixture is called synthesis gas (also known as syngas) or producer gas and is itself a fuel. The power derived from gasification and combustion of the resultant gas is considered to be a source of renewable energy if the gasified compounds were obtained from biomass.
The advantage of gasification is that using the synthesis gas is potentially more efficient than direct combustion of the original fuel because it can be combusted at higher temperatures or even in fuel cells. Synthesis gas may be burned directly in gas engines, used to produce methanol and hydrogen, or converted into liquid fuels. Gasification can also begin with material that would otherwise have been disposed of such as biodegradable waste. In addition, the high-temperature process can refine out corrosive ash elements such as chloride and potassium, allowing clean gas production from otherwise problematic fuels. Gasification of fossil fuels is currently widely used on industrial scales to generate electricity.